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arXiv · 1911.10302

Axisymmetric diffeomorphisms and ideal fluids on Riemannian 3-manifolds

Leandro Lichtenfelz·Gerard Misiolek·Stephen C. Preston
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Abstract

We study the Riemannian geometry of 3D axisymmetric ideal fluids. We prove that the $L^2$ exponential map on the group of volume-preserving diffeomorphisms of a $3$-manifold is Fredholm along axisymmetric flows with sufficiently small swirl. Along the way, we define the notions of axisymmetric and swirl-free diffeomorphisms of any manifold with suitable symmetries and show that such diffeomorphisms form a totally geodesic submanifold of infinite $L^2$ diameter inside the space of volume-preserving diffeomorphisms whose diameter is known to be finite. As examples we derive the axisymmetric Euler equations on $3$-manifolds equipped with each of Thurston's eight model geometries.

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Leandro Lichtenfelz, Gerard Misiolek, Stephen C. Preston. 2019-11-23. Axisymmetric diffeomorphisms and ideal fluids on Riemannian 3-manifolds. https://arxiv.org/abs/1911.10302

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